In the trucking and transportation industries, the use of wheeled flatbed trailers to ship goods is commonly known. To both protect the goods which are being shipped and contain debris therefrom, various trailer enclosure systems have been proposed which are extendable over part or all of the trailer bed. Typically trailer enclosure systems comprise a flexible cover or tarp which when deployed is suspended above the upper surface of the trailer bed by way of a series of metal bows or other support frame. Conventionally, the edges of the cover are secured along the sides of the trailer bed by ratchet straps or cables to maintain the cover in place during transportation.
The applicant's earlier Canadian Patent No. 2,460,703, issued 20 May 2008, which is incorporated herein by reference in its entirety, describes a retractable truck tarpaulin system which incorporates pivot arm-mounted rotatable winding spindles. An edge portion of the covering tarpaulin secured to the spindle is coiled or wound thereabout to permit access to the trailer along each longitudinal side. The applicant has appreciated that, depending upon the trailer configuration, pivot arms may be susceptible to damage where, for example, the trailer is provided with a trailer-mounted forklift. In particular, as the system described in Canadian Patent No. 2,460,703 operates to retract or deploy the tarpaulin by winding or unwinding the spindle as the pivot rods rotate, the spindle arm may be bent or damaged on being struck by the forklift as it is driven into the forklift mounting at the trailer end.
In addition, the use of forward pivot arms may interfere with the trailer cab exhaust, particularly on straight or non-articulating tucks.